EPA 608 609 - EPA Refrigerant Handling Type II High-Pressure Systems Questions and Answers 2 — Questions and Answers
Question 1: EPA Section 608 Type II certification covers which category of refrigeration and air conditioning equipment?
- Small appliances with hermetically sealed compressors and less than 5 lbs of refrigerant
- High-pressure systems other than small appliances (Correct answer)
- Low-pressure systems using refrigerants below atmospheric pressure
- Motor vehicle air conditioning systems
Correct answer: High-pressure systems other than small appliances
Type II certification under EPA Section 608 covers high-pressure systems other than small appliances. This includes most commercial and industrial refrigeration equipment, large split systems, rooftop units, and other high-pressure systems that contain refrigerants such as R-22, R-410A, R-404A, and similar refrigerants that operate above atmospheric pressure.
Question 2: Which refrigerant is classified as a high-pressure refrigerant and commonly used in commercial refrigeration Type II systems?
- R-11 (low-pressure)
- R-113 (low-pressure)
- R-404A (high-pressure) (Correct answer)
- R-123 (low-pressure)
Correct answer: R-404A (high-pressure)
R-404A is a high-pressure HFC refrigerant blend commonly used in commercial refrigeration, supermarket display cases, and transport refrigeration (Type II systems). R-11, R-113, and R-123 are low-pressure refrigerants that operate below atmospheric pressure at room temperature, requiring Type III certification to service.
Question 3: What is the normal operating suction pressure range for an R-410A air conditioning system at a 45°F evaporator saturation temperature?
- Approximately 30 psig
- Approximately 68 psig
- Approximately 102 psig (Correct answer)
- Approximately 130 psig
Correct answer: Approximately 102 psig
R-410A has significantly higher operating pressures than older refrigerants. At a 45°F saturated suction temperature (typical for comfort cooling), R-410A has a saturation pressure of approximately 102 psig. This is roughly twice the pressure of R-22 at the same temperature, which is why R-410A systems require higher-rated components and service equipment.
Question 4: Before opening a high-pressure refrigerant system for service, what must a certified technician always do first?
- Add a dye tracer to locate any existing leaks
- Recover the refrigerant charge to meet EPA requirements (Correct answer)
- Increase system pressure to test for leaks before opening
- Drain the oil from the compressor crankcase
Correct answer: Recover the refrigerant charge to meet EPA requirements
Before opening any refrigerant system for service (such as replacing components), the technician must first recover the refrigerant charge using EPA-certified recovery equipment. Venting refrigerant to the atmosphere is prohibited. Only after recovering the refrigerant to the required level may the system be opened safely.
Question 5: R-410A is a zeotropic blend refrigerant. What does this mean for technicians during leak and recharge situations?
- It must always be charged as a liquid because its blend components can fractionate (Correct answer)
- It can be charged as either vapor or liquid without affecting its composition
- It is an azeotropic blend that behaves like a single-component refrigerant
- It separates into its components at temperatures above 100°F
Correct answer: It must always be charged as a liquid because its blend components can fractionate
R-410A is technically near-azeotropic, but as a blended refrigerant it should be charged as a liquid (from the liquid valve on the cylinder) to maintain proper blend composition. If charged as vapor, the two components (R-32 and R-125) may fractionate — meaning lighter components escape first — altering the blend ratio and reducing system performance. Always charge blended refrigerants as liquid.
Question 6: What is the purpose of a liquid line filter-drier in a high-pressure refrigeration system?
- To reduce refrigerant velocity entering the expansion device
- To remove moisture, acid, and particulates from the refrigerant (Correct answer)
- To separate oil from refrigerant on the high-pressure side
- To prevent refrigerant from flowing backward through the compressor
Correct answer: To remove moisture, acid, and particulates from the refrigerant
The liquid line filter-drier serves two critical functions: it contains a desiccant (typically molecular sieve or silica gel) to absorb moisture from the refrigerant, and it contains a filter element to trap particulates such as metal shavings and system debris. Moisture forms acid with refrigerant oils, causing corrosion and compressor failure, so drier maintenance is essential.
EPA 608 609 - EPA Refrigerant Handling Type II High-Pressure Systems Questions and Answers 2
EPA Section 608 Type II certification covers which category of refrigeration and air conditioning equipment?